Ondansetron in Pregnancy Not Linked to Most Birth Defects

TUESDAY, Oct. 2, 2018 — Use of ondansetron for the treatment of nausea and vomiting in pregnancy does not appear to be associated with birth defects, according to research published in the August issue of Obstetrics & Gynecology.

Samantha E. Parker, Ph.D., from the Boston University School of Public Health, and colleagues used data from two case-control studies (the National Birth Defects Prevention Study and the Slone Birth Defects Study) to examine the prevalence of ondansetron use for treatment of first-trimester nausea and vomiting during pregnancy. The analyses included 6,751 and 5,873 control mothers, respectively, from each study and 14,667 and 8,533 case mothers who reported first-trimester nausea and vomiting.

The researchers found that ondansetron exposure increased from less than 1 percent before 2000 to 13 percent in 2013 to 2014 among women in the control group. For most of the 51 birth defect groups analyzed, ondansetron use was not associated with increased risk. In the National Birth Defects Prevention Study, modest increases in risk were seen for cleft palate (adjusted odds ratio, 1.6), while in the Birth Defects Study, there were modest increases for renal agenesis-dysgenesis (adjusted odds ratio, 1.8); however, these findings may be the result of chance.

“For the majority of specific birth defects investigated, there was no increased risk associated with first-trimester use of ondansetron for treatment of nausea and vomiting of pregnancy compared with no treatment, although modest associations with cleft palate and renal agenesis-dysgenesis warrant further study,” the authors write.